Published 8 April 2026 · 5 min read · Written with Pn. Aishah, Dawnplex senior technician
If you remember nothing else from this note, remember this: fogging without larviciding is theatre. The adult mosquitoes you see today are the result of eggs laid eight to twelve days ago. Kill them, and unless you’ve also drained or treated the water where the next batch is hatching, the air will be biting again next week.
Here is the four-step protocol Dawnplex crews run on every confirmed-case house visit and every JMB-commissioned cluster response. It works for a single bungalow and it works for a 600-unit condo.
Step one: a breeding survey, not a glance
The technician walks every accessible water-holding surface on the property, indoors and out, and lists each one. The non-obvious sites do the damage:
- Roof drains and downspouts. Especially the elbows — leaves catch, water sits.
- Plant trays. The single most common Aedes breeding site we find in Malaysian homes. The tray under that gardenia pot fits 30 ml of water and breeds 100 larvae.
- Aircon condensate. If the drip ends in a saucer, you have a hatchery.
- Bromeliads & pineapple plants. Their leaf-cup hold water — a classic Aedes spot.
- Discarded containers. Bottle caps, yoghurt tubs, dog bowls left in the rain.
- Gutters. If they slope wrong (or block with leaves), every storm leaves you a long, narrow swimming pool.
Step two: larviciding the unavoidable water
Some water can’t be tipped out — basement sumps, decorative fountains, the disabled-access manhole on your driveway. For those we apply BTI (Bacillus thuringiensis israelensis) granules. BTI is a bacterium that the larvae eat; it’s species-selective, harmless to mammals, fish and bees.
For accessible voids that hold standing water more than three days but can’t be drained, we use an insect growth regulator (IGR). The larvae develop but can’t complete the moult to adult — they die in the water instead of flying away.
If we walk a site and there is no candidate water for larvicide, we are missing breeding sources. There is always water in a Malaysian property.
Step three: fog the adults, at the right hour
Aedes aegypti — the primary dengue vector — is most active in the two hours after sunrise and the two hours before sunset. That is when we fog. Cold-fog ULV droplets are 5–25 microns; they hang in the air long enough to coat resting adults during those windows. Mid-day fogging burns adulticide on dead air; night fogging hits the wrong species (Culex, which mostly carries Japanese encephalitis, not dengue).
We don’t fog in rain. We don’t fog into a strong wind. We don’t fog inside houses unless we’ve evacuated the residents first. None of that is optional — it’s on every Dawnplex job sheet.
Step four: re-audit at day fourteen
Two weeks after the initial visit, the same technician walks the same sites. They check the larvicide is still in place, they look for new breeding (you’d be surprised how many homeowners promptly leave a new flower tray out), and they run a brief BG-Sentinel or sticky trap count on adult activity. If adult numbers have rebounded, we fog again at no extra charge.
What homeowners can do today
Before any contractor visits, you can dismantle 70% of your breeding pressure in 30 minutes:
- Walk every planter outside and tip the tray. Don’t pour back into the pot — pour into the garden.
- Check the aircon condensate point. If it pools, either drain it or add a BTI granule pouch (your contractor can supply one).
- Look at your gutters at the next mid-day. Pooled water visible from the ground is a problem.
- Walk the carport. Bottle caps, takeaway lids, dog bowls — collect and bin.
JMB or RA: what to demand from your contractor
If you are on a strata or residential association committee, your dengue-prevention contractor should be giving you a monthly report with at least these elements:
- Larva site map (PDF, marked with date).
- List of larvicide applications by location.
- Adult fog log with weather notes.
- Activity trend chart (adult count) versus the previous three months.
If your contractor’s report is two photos and an invoice, the contract isn’t earning its money. Ask for the playbook.
Dengue case in your taman this week? Tell us where — Dawnplex slots confirmed-case responses ahead of routine work in Klang Valley.